I meaning online elsewhere. Kind of like uploading a photo to Photobucket and linking/posting with the URL from there. You may even be able to upload audio to photobucket. I googled and this is one option https://soundcloud.com/upload

I've never even been able to upload simple photos, I always get the message the file is too big

I find if the image is on the net you need to open the image into its own window and then copy and paste into the forum, otherwise, I get errors too. I don't use the URL thing! For your own images, copy your image into your FB, keep your FB images as private and again click on the image then copy and paste the image into the forum. Both these ways work well for me better than Photobucket that has gone offline sometimes.

I meaning online elsewhere. Kind of like uploading a photo to Photobucket and linking/posting with the URL from there. You may even be able to upload audio to photobucket. I googled and this is one option https://soundcloud.com/upload